I have Herodotus and Arrian. This series is extremely well researched and has a very appealing lay-out, extensive but concise foot notes, special commissioned geographical maps, and I could just go on and on praising this marvellous series.
The series has now its own homepage (including sample pages) at www.thelandmarkancienthistories.com
and there is an interesting talk about the concept and ideas behind the series by its founder Robert Strassler here: